Each telephone set must be coupled through a pair of telephone conductors or wires to a telephone central office. Normally, a multiplicity of pairs of insulated telephone conductors are grouped together in an insulated communication cable which is suspended from poles or buried in the ground so that service wires can be coupled to the telephone conductors at various locations remote from the telephone central office. The aerial connection from the distribution cable to an individual building is commonly referred to as the service drop.
This type of multiconductor communication cable normally includes two portions. One portion is an insulated cable containing the individually insulated telephone conductors (sometimes referred to as the cable core) enclosed in an inner metallic shield which is surrounded by an outer insulating sheath. The other portion of the communication cable is a support strand. This strand can have the insulated conductor cable lashed to it by appropriate lashing wire. Alternately, the communication cable can be of the integrated type with the support strand and the insulated conductor cable contained in a continuous common extruded insulating jacket such that the communication cable in cross section is in a figure eight type of configuration with a web of insulating material interconnecting the support strand and the conductor cable.
In order to couple the pairs of telephone wires within the communication cable to a telephone set at a remote location, such as at a house, service or drop wires are used which extend from the cable to the premises where the individual telephone set is located. The connection of the drop wires to the individual pairs of wires within the insulated cable of the communication cable can be accomplished in an aerial type of enclosure which is mounted on or supported by the support strand portion of the communication cable. These types of aerial enclosures have commonly been referred to as ready access closures, or aerial terminals, because they permit a serviceman access to the telephone conductors within the insulated conductor cable when a service drop needs to be connected to the cable and provide a certain amount of protection from the environment for these connections.
In a ready access closure, personnel have access to both the service wires extending into the closure and the conductors contained within the cable core after the jacket, including the outer insulating sheath and the inner metallic shield, has been removed. On the other hand, a fixed count type of terminal is designed so that the exposed cable core is somehow separated from the service wires. As a result, in such terminals a lesser trained installer or the like would not have ready access to the conductors in the communication cable.
When a ready access closure or fixed count terminal is to be mounted on a communication cable, a portion of the outer insulating sheath of the conductor cable must be stripped away and in the case of the integrated cable, the web interconnecting the conductor cable and the support strand must also be severed. In addition, the inner metallic shield of the conductor cable is removed from that portion to the cable such that the individual telephone conductors within the insulated cable are exposed and the connection to the drop wires may be made. Since the outer insulating jacket or sheath and the inner metallic shield are severed for a required distance along the communication cable, the closure or terminal must provide for the continuity of the shield when it is mounted over the exposed area of the communication cable.
Different types of ready access closure or fixed count terminals are disclosed in U.S. Pat. Nos. 3,153,693; 3,499,972; 3,701,835 and 3,846,575. The ready access closures disclosed in these patents have the disadvantage that a relatively unskilled serviceman or telephone installer has direct access to the telephone conductors within the insulated cable portion of the communication cable when service or drop wires are being coupled to the telephone conductors. Such installers may not be as skilled as the linemen or construction worker who installs the cable closure on the communication cable. As a result, the ready access closure can become so overcrowded and unmanageable that the inside of the closure is a "rats nest" of tangled wires and an installer who later needs to make connections in the closure can easily unintentionally disrupt the connection to one or more other previously connected telephone services when making such additional connections. Experience has shown this to be a substantial problem.
Moreover, there is a tendency for personnel to inappropriately tamper with conductors in the cable. For instance, when one pair of conductors is defective, an installer might make the service wire connection to another pair of conductors in the cable which are not supposed to be used in that particular closure, rather than finding the cause of the defect. Also, ready access closures make attractive homes and shelters for animals, particularly birds. Many animals, particularly rodents, will chew the conductors, thus severing them or removing insulation. These circumstances increase the number of faults, and thus maintenance cost to the operating company.
Some of the previously designed fixed count terminals do attempt to isolate the connections of the service wires to the telephone conductors in the communications cable from servicemen or installers by providing a fixed count terminal which is divided into two distinct sections or compartments. One section is for the communication cable and the other section for the service wires. Access to the two sections is through separate covers or doors, so that it is difficult for unauthorized personnel to obtain access to the conductors in the communication cable. This type of fixed count terminal is representatively shown in U.S. Pat. No. 4,390,744 issued June 28, 1983 to Suffi et al. A disadvantage still remains in that the door to the service wire compartment may be left ajar by service personnel thereby permitting moisture to migrate into the cable compartment via numerous penetrations through the wall within the terminal that separates the cable and fixed count compartments, both being internal of the terminal.
Furthermore, prior art fixed count terminals tend to be of rather complex construction, requiring a large number of individually fabricated parts.